Staged loading is the ability to pause an active load operation until additional data is available.
If a single table needs to be filled with the contents of three files, for example, usually all three files are streamed to look like a single source to Teradata PT. But if one of the files will not exist until the next day, it is possible to load in stages. In other words, Teradata PT can load the first two files, pause the Load operation, and then load the third file when it is available.
Staged loading is set by the attribute PauseAcq = 'Y', which prevents the Load operator from proceeding to the application phase. Each stage of the load operation is accomplished with a separate job script: one for the acquisition phase, and one for the application phase.
For example, to accomplish the scenario with three files (one of which is unavailable until the next day), run Job1 on Day 1 using the two existing files as input to the load, with the PauseAcq = 'Y' setting.
When this stage of the job is finished, the target table is paused and becomes inaccessible to users. Attempts to access the target table (or the error tables) return the following error message:
Operation Not Allowed <tablename> is being loaded
On Day 2, restart the paused job by running Job2 using the third, newly available file as input. For this stage, set PauseAcq = 'N'. When this stage of the job finishes, the table is fully loaded and ready for access.